Clarify various aspects of EC elections and the Union of Councils.

This change incorporates suggestions from the discussions at #251 and jupyter-governance/ec-team-compass#23.

executive_council.md

@@ -55,9 +55,9 @@ The [Executive Council Team Compass](https://executive-council-team-compass.read
 
 ## Council membership and elections
 
-The EC will consist of 6 Council members who serve 2-year terms. Members are elected from the body of the union of all Standing Committee, Working Group, and Subproject Councils ("Union of Councils", UoC). Any UoC member is eligible for candidacy in an election unless, as of the start of the new term, they have served on the EC for three or more of the last four years.
+The EC will consist of 6 Council members who serve 2-year terms. Members are elected from the body of the union of all Standing Committee, Working Group, and Subproject Councils ("Union of Councils", UoC). Any UoC member is eligible for candidacy in an election unless, as of the start of the new term, they have served on the EC for three or more of the last four years. Members are elected by either the UoC or the existing EC as described below, such that after each election, the cumulative total number of seats filled by the UoC is equal to, or one more than, the number filled by the EC.
 
-Each annual election will begin with the existing EC notifying the UoC of a call for nominations. Any member of the UoC may nominate a candidate, including themselves. The EC will confirm that a nominee accepts their nomination. The candidate shall write a statement of their interest, qualifications, experience, etc. that will be distributed to voters. Once the full set of candidates is assembled, the UoC and then the EC will take ranked choice votes to fill their allocated number of EC seats. After each election, the total number of seats filled by the UoC should be equal to, or one more than, the number filled by the EC.
+Each annual election will begin with the existing EC notifying the UoC of a call for nominations. Any member of the UoC may nominate a candidate, including themselves. The EC will confirm that a nominee is eligible and accepts their nomination. The candidate shall write a statement of their interest, qualifications, experience, etc., that will be distributed to voters. Once the full set of candidates is assembled, the UoC and then the EC will take ranked choice votes to fill their allocated number of EC seats.
 
 If a member leaves the council before the end of their term, the EC may designate an eligible replacement who will serve for the rest of the term. This replacement will count as a seat filled by the EC if the replacement serves more than half of the term.
 

overview.md

@@ -20,7 +20,7 @@ In addition to these three bodies, the following are other major parts of the Pr
 
 ### Software Subprojects
 
-[Software Subprojects](software_subprojects.md) in the Jupyter community are official areas of focus and effort within the Jupyter ecosystem. They often map to a single GitHub organization. Subprojects must abide by the [Jupyter Code of Conduct](conduct/code_of_conduct.md), Jupyter decision-making and governance processes (e.g. respecting the project's trademark policies), as well as commit to certain technical limitations and scope. Each subproject elects one person to serve on the Software Steering Council. For more details, see the [Software Subprojects document](software_subprojects.md).
+[Software Subprojects](software_subprojects.md) in the Jupyter community are official areas of focus and effort within the Jupyter ecosystem. They often map to a single GitHub organization. Subprojects must abide by the [Jupyter Code of Conduct](conduct/code_of_conduct.md), Jupyter decision-making and governance processes (e.g. respecting the project's trademark policies), as well as commit to certain technical limitations and scope. Each Subproject maintains a Subproject Council and elects one person from the Subproject Council to serve on the Software Steering Council. For more details, see the [Software Subprojects document](software_subprojects.md).
 
 ### Standing Committees and Working Groups
 
@@ -30,6 +30,10 @@ The primary difference between Standing Committees and Working Groups is that St
 
 For more details, see the [Standing Committess and Working Groups document](standing_committees_and_working_groups.md).
 
+### Union of Councils
+
+The Union of Councils (UoC) is the union of the membership of all Subproject Councils, Standing Committees, and Working Groups. The UoC is the body from which [Executive Council](executive_council.md) are elected, and the UoC votes on the membership of the [Executive Council](executive_council.md).
+
 ### Distinguished Contributors
 
 The [Distinguished Contributors](distinguished_contributors.md) are a group of Jupyter community members that have gone above-and-beyond in their support of the project over the years, making substantial and sustained contributions in any area of activity (software development, governance, community engagement, events, etc.). The Jupyter community confers membership in this group as a way of recognizing their effort and saying “thank you.” For more details, see the [Distinguished Contributors document](distinguished_contributors.md).